Saudi Arabia on Saturday arrested 11 princes and dozens of current and former ministers in a sweeping crackdown headed by the kingdom’s young crown prince, Mohammed bin Salman.

In what has also been described as a move to consolidate power by MBS, the head of the Saudi National Guard and once a leading contender to the throne was replaced in a high-profile purge that sent shock waves across the conservative kingdom.

The crackdown follows a new anti-corruption commission established by royal decree late Saturday and headed by the powerful MBS.

According to Saudi-owned Al Arabiya television, the princes, including prominent billionaire Prince Al-Waleed bin Talal, and four current and dozens of former ministers were arrested as the commission launched a probe into old cases such as floods that devastated the Red Sea city of Jeddah in 2009.

State-run Saudi Press Agency said the commission’s goal was to “preserve public money, punish corrupt people and those who exploit their positions”.

The move also got religious backing after the kingdom’s top council of clerics tweeted that anti-corruption efforts were “as important as the fight against terrorism”.

“The breadth and scale of the arrests appears to be unprecedented in modern Saudi history,” said Kristian Ulrichsen, a fellow at the Baker Institute for Public Policy at Rice University.

“The reported detention of Prince Al-Waleed bin Talal, if true, would send shock waves through the domestic and international business community,” Ulrichsen told AFP.

The purge comes less than two weeks after Prince Mohammed welcomed thousands of global business titans to Riyadh for an investment summit, and in the wake of sweeping reforms in the kingdom that allows more freedom end economic opportunities for women.

It also follows a wave of arrests of influential clerics and activists that were resistant to Prince Mohammed’s aggressive foreign policy as he moves to consolidate control of the kingdom’s security institutions.

Already viewed as the de facto ruler of the kingdom, analysts believe MBS is stamping out traces of internal dissent before a formal transfer of power from his 81-year-old father King Salman.

He’s been predicted to be the first millennial to occupy the Saudi throne, and some expect him to rule for over a half century.